Load handling attachment for fork lift trucks



A. M. VIK

May 16, 1967 LOAD HANDLING ATTACHMENT FOR FORK LIFT TRUCKS 2 Sheets-Sheet 1 Filed Sept. 24, 1964 FIG. 2

INVENTOR. ALBA!" M V//( ATTORNEY 16, 1967 A. M. VIK 3,319,815

LOAD HANDLING ATTACHMENT FOR FORK LIFT TRUCKS F16. [3. FIG. 14 715. 1.5

INVENTOR.

ALBAM M. WK

ATTORNEY United States Patent 3,319,815 LUAD HANDLING ATTACHMENT FDR FQRK LIFT TRUCKS Albam M. Vik, New Brighton, Minn, assignor to Tameo, Inc, St. Paul, Minn., a corporation of Minnesota Filed Sept. 24, 1964, Ser. No. 398,889 3 Claims. (Cl.,214-62li) This invention relates to a load handling attachment for fork lift trucks; in particular, it concerns apparatus that is slidably mountable on the forks of an industrial fork lift truck to permit the truck to handle drums, containers, paper rolls and the like with great efliciency and ease.

The general object of the invention is to provide an improved load handling attachment for fork lift trucks. Other objects of the invention are: to provide an improved load handling apparatus for fork lift trucks characterized by a pair of gripping members movable in two planes for receiving, gripping and releasing a load; to provide improved apparatus of this type including novel means for mounting the gripping members with respect to the forks; to provide an improved detachable load handling device for slipping on the forks of a. lift truck including novel means for mounting and guiding the load handling elements for limited pivotal movement with respect to the forks and the load whereby to receive, grip and release the load pursuant to the movement of the truck and the forks and independent of operator control of the device; to provide improved apparatus of this type including novel means for setting the distance between the load handling elements to correspond to the width of the load to be handled; to provide improved apparatus of this type including novel means for indicating the distance between the load handling elements of the device; to provide a new and improved load handling attachment for removably mounting on the forks of an industrial lift truck including novel means for urging the load handling elements in a given direction; and in general, to provide improved apparatus of the type described which is highly versatile and dependable in operation, simple and inexpensive to construct, and rugged and long wearing in service.

The foregoing and other objects and advantages of the invention will become apparent from a consideration of the following detailed description taken in conjunction with the drawings wherein a representative embodiment of the invention is shown by way of illustration and not by way of limitation.

In the drawings:

FIGURE 1 is a side view of the invention mounted on a framentarily shown fork lift truck;

FIGURE 2 is a top view of the assembly shown in FIGURE 1;

FIGURE 3 is a sectional view taken on the line 3-3 of FIGURE 2;

FIGURE 4 is a view, partially in section, taken on the line 4-4 of FIGURE 2;

FIGURE 5 is a view, partially in section, taken on the line 55 of FIGURE 2;

FIGURE 6 is a view, partially in section, taken on the line 66 of FIGURE 2;

FIGURE 7 is an enlarged fragmentary view, partially in section, taken on the line 7-7 of FIGURE 2;

FIGURE 8 is an enlarged fragmentary top view of an alternate gripping jaw used in the invention;

FIGURE 9 is a sectional View taken on the line 99 of FIGURE 8;

FIGURE 10 is a view similar to FIGURE 8 showing another form of gripping jaw used in the invention;

FIGURE 11 is a view, partially in section, taken on the line 11-11 of FIGURE 10;

3,3 l 9,8 l5 Patented May 16, E967 FIGURE 12 is a sectional view taken on the line 12 12 of FIGURE 10;

FIGURE 13 is a fragmentary side and top view on a reduced scale showing the lowered position of one of the gripping jaws on the fork upon initially contacting a drum;

FIGURE 14 is a view similar to FIGURE 13 showing the gripping jaw in an elevated drum receiving position; and

FIGURE 15 is a view similar to FIGURES 13 and 14 showing the gripping jaw assuming a drum gripping position pursuant to raising of the forks with respect to the drum.

Generally speaking, according to the principles of my invention, I provide a readily demountable load handling attachment for fork lift trucks adapted to be slipped on over the forks and operated entirely by manuevering the truck. The device is equipped with a pair of opposed load gripping members having inwardly facing jaws that contact and grippingly engage the load when the weight of the load is applied thereto by elevating the forks. The load gripping members, pivotally mounted at their rear ends upon a slip-on base structure, are adapted to move upwardly and outwardly from a normally downwardly and inwardly disposed position to permit the receiving of a drum or other load therebetween. When the jaws of the gripping members surroundingly engage the eriphery of the drum, the forks are raised causing the jaws to move downwardly and inwardly with respect to the forks and the drum thereby exerting a strong clamping action upon opposed peripheral portions of the drum. The drum is firmly held between the jaws until the pressure exerted by the weight of the drum is relieved by setting the drum down and lowering the forks with respect thereto. The base structure for the device includes a pair of hollow supports that slip on over the forks. These are connected laterally by structural members that telescope with respect to each other to provide a laterally adjustable base structure for dilferent fork widths adapted to accommodate various widths of drums and other loads. The base structure is equipped with a pointer and indi-cia combination permitting one to readily set the distance between the forks according to commonly experienced load dimensions; for example, the embodiment shown herein illustrates the aforementioned indicia as applied to conventional 30 and 55 gallon steel drums.

Turning now to the drawings, FIGURES l and 2 illustrate the invention A mounted on the forwardly extending lifting forks 2t 22 of a conventional industrial type mobile lift truck B. A steel drum C, indicated in dotted lines in FIGURES 1 and 2, is shown being carried by the device A between and slightly forwardly of the forks 20 and 22. The device includes a base structure 24 consisting of a pair of identical hollow supports 26, 28 formed of steel and characterized by a generally rectangular crosssection adapted to slip over and engage forks 20 and 22. As shown in FIGURE 6, supports 26, 28 are capped at their forward ends, as at 30, to position the base structure 24 on the front portion of the forks. A hollow laterally extending guide member 32, secured to the top of support member 26 adjacent its rear end, is adapted to slidably telescopically receive therein a laterally inwardly extending connector 34 which is secured to the top of support 28 in alignment with guide member 32. A hole 36 through guide member 32 is located in line with a series of matching holes 38 in connector 34; pin 40 is provided which extends through hole 36 and one of the diodes 38 to permit a selective lateral positioning of the supports 26, 28- according to the width or diameter of the load to be carried and the distance between forks 2t), 22. A chain 41 may be provided to prevent loss of the pin 49. In the case of steel drums, it is well known that two sizes are predominant, i.e., the SD-gallon and the SS-gallon sizes. To permit the ready setting of the forks into position to receive and carry these sizes, I have placed suitable indicia 42 upon the connector 34 corresponding to these widths and also provide a pointer 4-4 so located upon guide member 32 as to line up with the proper indicia 42 when the holes 36 and 38 are in alignment with these widths. The indicia 42 may be painted upon the connector 34 if desired although a decal or other suitable marking means may be used.

The drum C is supported by a pair of opposed gripping members 50, 52 which clampingly engage peripheral portions of the drum, as will be explained. Gripping members 50 and 52, being of reversed formation but otherwise identical, include forwardly extending generally elongated arms 54, 56 overlying supports 26, 28 and pivotally secured at their rear ends to brackets 58 and 60, which are positioned on supports 26, 28 adjacent guide 32 and connector 34, as shown in FIGURE 2 of the drawings. The rear ends of arms 54, 56 terminate in laterally extending hollow bushing-like members 62, 64, which are slightly flattened from a true circular cross-section to a generally oval cross-section, as more particularly shown in FIGURE 6. The lateral faces of the members 62, 64 are machined, as at 66, 68 to provide clearance at their corners. Brackets 58 and 60 each include a pair of laterally spaced upstanding lugs 70, 72 through which bolts 74, 76 extend for mounting members 62 and 64 of arms 54, 56. As shown in FIGURE 7, the flattened crosssectional shape of bushing-like members 62, 64 provides longitudinal clearance 78 between the bolts 74, 76 and the internal surfaces of members 62, 64. This clearance and the clearance provided by the relieved corners 66, 68 of members 62, 64 results in a loosely fitting pivotal mounting for the rear ends of arms 54, and 56. This construction permits arms 54 and S6 to pivot in two planes with respect to the fork, that is to say, a limited amount of lateral and vertical movement of the arms is afforded by this arrangement. The forward ends of the arms 54, 56 are equipped with inwardly facing opposed jaws 80, 82, which are of a curved or arcuate configuration. The inner drum contacting surface of the jaws are provided with rubber or similar resilient liners 84, 86.

To limit and control the hereinabove described loose pivotal movement of the gripping members 50, 52, about their rear ends, I provide a pair of laterally extending upright guide brackets 88, 90, which are located on the top of and adjacent the forward ends of support members 26 and 28. Guide brackets 88, 90 are characterized by plate-like bodies 92, 94 that are welded to the support members 26, 28 and are provided with downwardly and inwardly converging slots 96, 98 adapted to slidably receive middle portions of arms 54, 56, respectively, of gripping members 50 and 52. A pair of removable cross bars 100, 102 are bolted to the top of brackets 88, 90 to close in the upper ends of the slots 96, 98 and limit the upward and outward displacement of arms 54, 56 therein. Further provided are a pair of tension spring members 104, 106 which serve a booster function in maintaining the gripping members 50, 52 in a normally inwardly and downwardly disposed position at the bottom of the inclined slots 96, 98. They are supported at their upper end by means of a pair of upstanding and outwardly inclined support bars 108 and 110 fastened to arms 54, 56. Their lower ends are secured to brackets 112, 114 which are mounted on the top of support members 26 and 28. It is thus apparent that gripping members 50, 52 pivotally move about their rear ends according to the path provided by guide slots 96 and 98 in brackets 88 and 90. The jaws 80 and 82 are in a normally lowered and converging position at the bottom of the slots 96, 98 due to the force of gravity tending to pivot them about their rear ends, as explained; springs 104, 106 supplement the force of gravity in urging the jaws into a normally lowered and converging position. Springs 104, 106 also serve to dampen the movement of the jaws upwardly and outwardly as the arms 54, 56 ride in slots 96, 98 and tend to make the jaws coact in a smooth and positive manner.

FIGURES 8 and 9 illustrate an alternate form of jaw construction for gripping members 50, 52. The jaw body 116 is cut from a piece of angle iron with the top flange 118 thereof being cut in semi-circular shape, as at 120 to permit it to engage a drum rib or other lateral projection on a load, if desired.

In FIGURES 10 through 12, a third form of jaw construction for gripping members 50, 52 is set forth. In this embodiment, a longitudinally extending fiat jaw 124, provided with a resilient flat inner face 126, is pivotally mounted by means of a laterally outwardly extending bracket 128 to each end of arms 54, 56 of gripping members 50, 52. A vertical pin connection 130 permits the oscillation of each jaw 124 about a central vertical axis. The inward oscillation of each jaw 124 is limited by contact with its respective arm while its outward oscillation is limited by means of a yoke 132 which surroundingly engages the arm rearwardly of pin connection 130. Jaws of this type may be used for handling loads of non-circular shapes such as shipping boxes and other containers of cubical or rectangular shape. Any of the three jaws shown may be easily interchanged by removing the cross bars 100, 102 and bolts 74, 76 and substituting different gripping members with the desired jaw configuration.

The device is held against forward displacement on the forks by means of a chain that is fastened at its lower end to connector 34. A hook 142 at its upper end is used to secure the chain 140 to a cross bar or other convenient anchor point on the fork tower or truck.

FIGURES 13 through 15 illustrate the manner in which the device is used to receive, grip and release a load solely through operator control of the lift truck. Although a steel drum is shown and described herein, it should be understood that the device is well suited for handling other types of loads including paper rolls, boxes, containers and the like. Referring to FIGURE 13, the gripping members are shown in a normally downwardly and inwardly disposed position with respect to the forks and the drum. When the forward ends of the gripping members contact the drum they are forced upwardly and outwardly by the movement of the lift truck relative to the drum, as indicated by the arrows in FIGURES l3 and 14. This spreads the gripping members apart laterally and causes them to rise into peripheral contact with the drum. When the gripping members are surroundingly positioned with respect to opposed portions of the drum periphery, the operator raises the forks causing the gripping members to drop in their guide slots and clampingly engage the drum as the weight of the drum is applied thereto, as shown in FIGURE 15. The resulting clamping action positively holds the drum against falling out or being displaced as the natural tendency of the gripping members is to ride down in the slots towards each other. This tendency is accentuated by the Weight of the drum and the clamping action described is in no way dependent upon the drum ribs for its effectiveness. When the forks are raised it is impossible for the drum to slip out of the rigid seat provided by the gripping members until the forks are lowered and the weight of the drum is removed from the gripping members. When this is done, the gripping members again spread apart and travel upwardly in their guide slots to permit the truck to be backed away to thereby release the drum.

I desire it to be understood that this invention is not to be limited to any particular form or arrangement of parts except in so far as such limitations are included in the claims.

I claim:

1. In a drum handling attachment for fork lift trucks including a pair of opposed supports slidable over the ends of the forks, a pair of opposed drum gripping members 5. carried by said supports for supporting a drum therebetween by clamping engagement with peripheral portions of the drum, the combination of:

(a) laterally adjustable means connecting said supports and adapted to selectively position said drum gripping members in a predetermined laterally spaced relation to each other according to the size of the drum to be carried, including:

(1) a hollow laterally disposed member mounted on one of said supports;

(2) a laterally disposed connector mounted on the other of said supports and slidably positioned for lateral movement within said hollow member said connector having at least two drum size indicia thereon;

(3) means for releasing locking said member and said connector together in selected lateral positions; and

(b) means associated with said laterally adjustable means for indicating the size of the drum to be carried by said drum gripping means.

2. The structure set forth in claim 1 wherein said indicating means includes a pointer mounted on said hollow member cooperable with the said indicia on said connector for positioning said supports in laterally spaced relationship to each other whereby to space said gripping members according to the size of drum indicated by the indicia.

3. A drum handling attachment for fork lift trucks including:

(a) a pair of opposed supports slidable over the ends of the forks;

(b) a pair of opposed drum gripping members carried respectively by said supports for supporting a load therebetween by clamping engagement with peripheral portions of the load, said members including:

(1) forwardly extending gripping elements overlying said supports;

(2) means pivotally mounting the rear end of at least one of said elements permitting lateral and vertical movement of said element with respect to the other of said elements, and

(3) camming means intermediate the ends of said one of said elements for guiding the same in both a lateral and vertical direction to move said element into gripping engagement with the load when the forks are raised and releasing from engagement with the load when the forks are lowered,

(c) laterally adjustable means connecting said supports and adapted to selectively position said drum gripping members in a predetermined laterally spaced relation to each other according to the size of the drum to be carried, including:

(1) a hollow laterally disposed member mounted on one of said supports;

(2) a laterally disposed connector mounted on the other of said supports and slidably positioned for lateral movement within said hollow member said connector having at least two drum size indicia thereon.

References Cited by the Examiner UNITED STATES PATENTS 2,512,409 6/ 1950 Addie 214-653 2,704,167 3/ 1955 Framhein 214-653 2,755,949 7/ 1956 Schenkelberger 214653 2,827,189 3/ 1958 Knudstrup 214626 2,842,275 7/1958 Kughler 214-653 2,848,128 8/ 1958 Thompson 214-653 2,948,428 8/ 1960 Kughler 214653 3,172,693 3/1965 Hansen 214653 3,180,512 4/1965 Moss 214-62O 3,227,299 1/1966 Draxler 214-653 FOREIGN PATENTS 224,855 10/ 1962 Austria.

GERALD M. FORLENZA, Primary Examiner.

R. B. JOHNSON, Assistant Examiner. 

1. IN A DRUM HANDLING ATACHMENT FOR FORK LIFT TRUCKS INCLUDING A PAIR OF OPPOSED SUPPORTS SLIDABLE OVER THE ENDS OF THE FORKS, A PAIR OF OPPOSED DRUM GRIPPING MEMBERS CARRIED BY SAID SUPPORTS FOR SUPPORTING A DRUM THEREBETWEEN BY CLAMPING ENGAGEMENT WITH PERIPHERAL PORTIONS OF THE DRUM, THE COMBINATION OF: (A) LATERALLY ADJUSTABLE MEANS CONNECTING SAID SUPPORTS AND ADAPTED TO SELECTIVELY POSITION SAID DRUM GRIPPING MEMBERS IN A PREDETERMINED LATERALLY SPACED RELATION TO EACH OTHER ACCORDING TO THE SIZE OF THE DRUM TO BE CARRIED, INCLUDING: (1) A HOLLOW LATERALLY DISPOSED MEMBER MOUNTED ON ONE OF SAID SUPPORTS; 